Sails powered ships for millennia; but then the convenience of energy-dense fuels displaced sails. As ship speeds eventually exceeded wind speeds, the consensus became that sails had no place in shipping and were relegated to hobbyists and sport. Fast forward a century and a half, and maritime shipping, like all other industries, is facing a reckoning to mitigate the greenhouse gasses produced by their activities.
The International Maritime Organization (IMO) has introduced new regulations which use a vessel’s Carbon Intensity Indicator (CII) to grade ships. This grading scale becomes more aggressive over time, and any ship with a poor grade must take corrective action. The corrective actions can be as non-invasive as reducing speed (aka: slow steaming) or as extreme as a retrofit to use a different, cleaner fuel source. This costs millions and takes a ship out of commission for months, and it’s difficult to ensure your (now more expensive) fuel is available at every port of call. Ship owners are hedging their bets that slow steaming will dominate their future, with ship order books full to reflect the increased capacity needed when containers take 20% longer to cross the ocean.
Or option three. There is sufficient wind on the ocean to power the entire shipping industry, if you’re willing to grab it. Wind Assisted Ship Propulsion (WASP) devices can be used as a corrective action to improve a vessel’s CII rating, without reducing ship speed or changing the route. In other words, a return of sails.
We are hardware engineers with over two decades of experience between us, working at Tesla, SpaceX, JPL, Relativity, and some startups. The idea for OutSail came from Arpan and Joseph getting coffee after work one day. When we asked each other “What would you do if you weren’t building satellites?” maritime cargo came up from both sides; Arpan from having studied the industry for opportunities to reduce emissions, and Joseph from a love of hydrodynamics and maybe too many sea-shanties. Bailey and Arpan, meanwhile, had been looking at working on bicycling infrastructure. What brought the three of us together was actually a Dungeons & Dragons game where we realized we made a good team! We settled on OutSail as a good fit for our hardware hacking mentality, trading in our druids staffs for spanners.
Aerodynamically, sails are simply vertical wings. Wind blowing across the vessel causes the sail to generate lift and drag, and the resultant vector has some forward component to pull the ship through the water. However, if the wind comes from an angle too close to the direction of travel, there is no thrust. As an added complication, the sail only sees the relative wind. If the ship travels faster, the wind will appear to come from closer and closer to the direction of travel, even if the true wind is coming from perpendicular to your course! Despite this, standard sails can still produce forward thrust as long as the wind is at least 20 degrees off from directly in front of the vessel. This is how our sails can still save power, even on a fast moving vessel.
There are many sail technologies out there. A common question we get asked is “Are you going to use flettner rotors/suction airfoils?”. Both of these technologies use power supplied by the ship to increase the lift produced by a surface; rotor-sails spin, and suction airfoils…suck? Each of these have a place, especially at low vessel speeds. But our customers ask us for a solution that works for container ships cruising at the relatively high speed of 22kt. At these speeds, the relative wind is almost always ahead of you, so lift/drag becomes more important. Powered sails suffer from poor lift/drag, both from the high induced drag from very high lift coefficients, and system losses from drawing on ship’s power. So no we are not going with flettner rotors/suction airfoils. While they are the new exciting technology on the block, if you factor in their power usage and high drag ratio, they are just not as practical as a simple sail.
So now that we’ve given a general summary of sailing, it’s time to explain how a 747 wing will ever fit inside a 9ft tall cargo container. It’s simple really: imagine a tape measure. In a tape measure a thin, flexible strip of metal is wound into a spiral. Then, when the metal is uncoiled, it naturally returns to its original shape. That’s exactly how we plan to make our sails. The skin of our sail or the inner spars (we haven’t finalized our design) will be made of tape measure like material (2mm thick steel) and the wing will be able to extend out of the cargo container. The video in the first paragraph explains this in a bit more detail.
By fitting our sail into a cargo container we allow for our device to be installed on any cargo ship right at port. Remember how we mentioned that some shippers are ordering a lot more ships and some ships are getting retrofitted with new fuel? Well, shipyards are backed up for the next 5 years. By making a device that requires no shipyard to install, not only will we drastically outcompete other retrofit WASP companies in terms of deployment cost, but we will be the only company with a product shippers can put on their ship without a multiple year wait time.
Do you have any interesting stories around sailing or wind tech? We would love to hear your ideas, experiences, and feedback on any and all of the above!
[1] now at https://sfba.social/@sfships; formerly at https://twitter.com/sfships
[2] They said it was unsinkable, but as a software developer clearly I'm more talented than the norm.
[3] https://en.wikipedia.org/wiki/J/22
https://www.linkedin.com/company/OutSail-Shipping/
Once you took sailing classes at the place, you could take one out. My first time out on my own I backwinded the jib, which knocked it down. Then my non-sailor friends grabbed for the top rail, turtling the boat. Eventually we got it back up and started bailing, but it kept getting lower in the water, so we all jumped out again. The back then pretty rapidly sank, leaving a foot of the mast and a foot of the bow above the water. That left us treading water two miles offshore on a quiet Wednesday afternoon.
As you might imagine, I haven't done a lot of sailing since.
Why steel? Durability I assume? Have you modeled using a textile?
Do you have load sensors throughout the wing? Anemometors?
How active is the trimming? Is it just a single axis of rotation or do you have the ability to adjust the leech and luff shape? If so do you have the ability to adjust both the leeward and windward skins? Or just the windward? 2mm steel seems like it has a decent amount of play at that scale? Have you built any bigger scale models with steel? Feels to me like iteration time would take a significant hit playing with steel instead of cloth?
As consistent as these ships are with their speed under motor, the apparent wind will be all over the place. Could see apparent from 50+ on the nose to 5 knots from dead astern. Do you intend to have a fixed set of optimal wind velocities and trim settings? Or want to make something that is usable and automatic in anything but the most violent of breezes?
How much of the bill-of-materials is custom and how much is off-the-shelf type components and structural bits? Any custom composite parts or fairly off the shelf steel tubing, bar, and such?
Also are you hiring?
For load sensors, we're thinking strain gauges and pressure sensors to measure wing surface pressure and use that for live feedback. Anemometers might be mounted on the top of the wing, but more likely we'll use a master anemometer at the bridge to send info to the entire array.
For the wing shape, we're currently looking at a symmetric airfoil with fixed ribs inside for strength, so not able to actively change the camber, but we are looking at the ability to do wing warping to change the overall shape of the wing. We are still working to get our first data from on the water, so no good answers on the trim other than we want to make this as automatic and turnkey for the ship master as possible. We're quite early in the design still, though, so don't yet know where the limits of the technology are. Likewise, no answers on BOM and sourcing for you. However, we do plan to start hiring after our seed raise, so feel free to contact us through our website!
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> For load sensors, we're thinking strain gauges and pressure sensors
"We're looking"? "We're thinking"? Considering your demo video was a guy showing off folded printer paper secured with duct tape, and a gauzy fabric built around an off-the-shelf tape measure....
How far along are you? Sounds like you're nowhere even near a prototype, let alone a beta design. I know every company has gone through a design phase and a (sometimes lengthy) build up... but you don't usually see them start the PR hype train before they've even got a CGI demo or a model that isn't made out of scrap. What is it that makes you a real company, and not just some guy who got real excited about an idea he had last week?
I'd imagine the last 1-2 generations of America's Cup boats would have a lot to glean in terms of wing sail camber changes and how they operate. Pretty neat to watch how they use flaps vertically, but there's a lot of hydraulics and carbon at play there as well.
Maybe the competition is these guys? (Inflatable sails) https://www.michelin.com/en/press-releases/michelin-continue...
And something a bit more conventional off the bow when winds are favorable? https://skysails-marine.com/
Have you done any weather routing calcs to see what the angle of attack for the big ship lanes? Perhaps an integrated trip cost-benefit?
Also, you might not want to use the WASP acronym and stick with just "wind-assisted propulsion". The wind industry will immediately think of the WAsP software [0].
[0] https://www.wasp.dk/
Our design evolved out of a routing/performance analysis software that we run on historical weather data. Angle of attack and trip cost-benefit varies per lane. In general transpacific and transatlantic have amazing winds, with other routes performing well but not at well.
We've done the excel-level analyses on container loads and wing buckling forces. It all checks out. There is a combined-load case at 15deg of roll with heavy containers and heavy winds that's zero-margin, but as you said we can reef when required. Reefing will likely be single-digit minutes, but we can also feather (0 angle of attack) much more quickly.
Bailey has written a routing software which we use to send virtual ships on crossings (for instance Trans Pacific), incorporating historical weather data. Even with no change in route or vessel speed, we can see benefits.
Yikes. Containers are stacked as high as they can be to not crush the containers below. Applying additional downward force is going to cause cascading failures.
You've also just limited your deployment to routes that have double-stack container cranes, which AFAIK aren't that widely deployed.
Have you guys actually talked to anyone in the shipping industry or visited a cargo shipyard yet?
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https://alsum.co/wp-content/uploads/2021/04/Perdida-de-conte...
Look at a purpose-built sailship from the age of sail in a north Atlantic storm. It is a rough ride.
https://www.youtube.com/watch?v=Y7RABaByP_8
Another attempt in a similar fashion is the Oceanbird concept by Wallenius Wilhelmsen, but that means building the vessel from the ground to handle the forces and that over-head loading and unloading is not possible, thus the aim at RO-RO ships.
https://www.theoceanbird.com/
With one vessel already ordered:
https://www.walleniuswilhelmsen.com/news-and-insights/highli...
Personally, as a commercial sailor and software engineer, this container approach screams of VCs throwing money at commercial shipping without understanding the industry. Profit margins are non-existent and are already hugely optimized with possibilities for specialized solutions. This wing sail will have to compete with synthetic fuels without increasing the cost due to crewing requirements.
Oceanbird is awesome! The trouble is that overhauling the entire industry with new-built ships would take too long to make a meaningful climate impact, and be extremely expensive (not to mention that their approach only works for ro-ros).
Synthetic fuels will compete with aviation for the green hydrogen supply (needed to make methanol/ammonia/green hydrocarbons) and are expected to cost 2-3x what current fuels cost. This net makes our fuel cost savings case even stronger.
Industry insiders generally already know that there's really no good cost-saving decarbonization solution, and that decarbonizing fast is a hair-on-fire problem for owner/operators. The barriers standing in the way of most wind-assist devices are: poor ROI, shipyard availability for retrofits, risk to shipwoner (capital upfront), and that they don't package on containerships. We solve all these problems by using a large, efficient wing and depending on the container load path. There are technical problems to solve, but the fundamental physics works.
Have you actually talked to anyone in the cargo ship industry about your idea?
Shipping is responsible for like 2% of emissions. A 5-10-20% reduction on a small number of vessels for a small number of voyages is not gonna make a dent.
You would fold these down rather than trying to ride out a swell with them up. They go out of they way to clarify how easily these can be furled and unfurled.
Being fair, this is really broad and doesn't mean much at all.
Just like a jetliner wing that can be folded up. On the plus side, jetliners regularly hit speeds relative to the air that are ten times as fast
"What brought the three of us together was actually a Dungeons & Dragons game"
is the best part.
Feel free to hit me up (contact info in my profile) if you need a pep talk or intros to different circle of potential investors or friendly advice about web performance. Otherwise I'll be following your story and cheering you on from the sidelines.
I used to be part of a team back in university making autonomous sailboats [1] and one of the things that I was surprised by when working on this was that there are a TON of hurricanes out in the middle of the ocean (we were working to build it to cross the Atlantic). We built a system to take in weather prediction data to try to avoid hurricanes, but we were building a relatively tiny boat—do large shipping vessels do this as well? I'd assume they can sail through pretty bad weather. If so, do you have ways to lower the sails easily to protect them?
Additionally, do you have any software to help inform the vessel operators how to best sail into the wind or are the net savings not worth it considering most of the propulsion is still coming from fuel-based sources?
Overall, this is super exciting and best of luck!
[1] Now at (https://www.ubcsailbot.org/)
I was on a cargo ship in the pacific which diverted into the Bering Sea to avoid some weather instead of skirting just south of the Aleutian Islands as planned. The captain gots orders via satellite from a land crew that's crunching the numbers of risk vs extra fuel costs at all times for the fleet. The first mate was frustrated by how this all works. He said (English not being his first language): "This is terrible! We never get to decide anything for ourselves. We are like Muppets!". I think he meant "puppets"...
The shipping industry was 100% wind powered, with very mature technology developed and tried during centuries, and thousands upon thousands of experts in the area. Why do you think the whole industry switched to engines?
We also used to have windmills to grind grain and then switched over to mills that use electricity or fossil fuels. But of course, windmills to generate electricity have become quite popular. What's old can be new again when combined with modern technologies.
New breakthroughs in transportation is the need of the hour.
One of the reasons the world is teetering on a recession right now is there has been not a lot of physical changes to the world around us to create new worlds which software can then eat again.
Projects like this then, give me a lot of hope.